Ok, that resistor assortment looks much better than I expected.  I was worried there might just be 500 individual resistors thrown in a bag for you to sort out.  Looks like they are separated by value, with more of the most common values.  Price is reasonable, the only thing to keep in mind is they are 1/4 watt, which is fine for any battery operated device, but may not be useable in some other powered circuits you may build in the future.

Most of those prices you paid are fairly reasonable, except for the very generic individual electronic components, like the caps, led, and battery snaps.
It's fine for a one off project, but if you do more building check an actual electronic supplier such as Mouser, Newark, Digi-key, etc.
  As Roly pointed out, simple items like some of those caps are inflated 10 to 100 times for price.

 Ilyaa:  You probably read about it, but I'll mention it for others who may read this thread, the bias circuit you posted with the resistor that connects to the HV AC,
(http://music-electronics-forum.com/attachments/547d1175892694-kscan_0001.gif) that circuit will only work if the PT is center-tapped.

  This is with or without the transformer?

  Just a few more comments to add to what others have mentioned.
Lower gauge number wire is thicker, so it will always be able to handle the current, but may be stiffer and more difficult to work with, in this case I think 22ga will work fine instead of 24.
  A 1K trimmer is not a switch, it is a trim pot.  Generally, trimpots are miniature versions of pots that are adjustable with a screwdriver rather than a knob.
  Pretty much any .1uF cap  will be rated at least for 16V, so any should work.
Big bags of assorted parts are not always a good value, some times there may be 3 useful ones and a hundred you will never use.  In this case, I don't know how many different values of resistors they have in that assortment.  If it's a lot, you will have a hard time sorting through all those color codes to find the ones you want.

And I agree with Roly, $80 seems quite high.  Could you do a breakdown of the more expensive items?  If some are ridiculous, perhaps you could take them back and get them elsewhere.  I had thought this would be quite a cheap project, if a lot of it is general supplies not specific to this unit, then that is more understandable.

attached is the elusive schematic for this version, full page view on page 5 of pdf

  Maybe this will help.  They don't want the pdf posted elsewhere but here is a link to it:
http://www.generalguitargadgets.com/pdf/ggg_ruby.pdf

and some more
http://www.rustybrooks.com/electronics/mouser/kits?kit=rubyamp

http://rubyamp.com/build.html

http://www.instructables.com/community/Ruby-amp-9v-DIY-guitar-amp/

  Could you please do them one at a time and see which was the problem?  That way we will have a definitive solution to the issue, which may come up again.

  Measure the resistance across D4 (regulator input) and C18 (regulator output).

  I think he was looking at the schematic from the Randall thread, I don't see a 33V zener here.

  The standby switch problem stops the amp from working at all, so that is not your problem.
  If you have a tube that is not lit up, replace it.

  Sounds like it may be breaking into oscillation, causing volume loss and turning on the LED?

Quote from: gbono on September 02, 2014, 07:12:16 PM
When I lift R63 on the -9V supply I get -9V at ZD5 - someting is loading down the supply - but what?

Try the same check with R14 and R23, should help isolate the problem a bit more.

  Sorry, I seem to have messed up with my interpretation of "breadboard".  I was thinking you meant perfboard (vero or strip board) like the picture Roly posted.
  The radio shack breadboard you have is what I call "protoboard" and is not suitable for a permanent installation (and way more expensive).

Breadboard can be used for prototyping or building.  As this is a one off project you can use the breadboard as the finished product.  If you decide you want to go into production, it would be easier to use printed circuit boards.

The 386 suffix denotes how much voltage the IC can withstand, any version is good for at least 9V, so you don't need to worry about it.

Fuses are optional.  You can't hurt yourself with a 9V battery (unless you really wanted to, and connect wires to it that you pierce your skin with).

  It's hard to believe how hot some of these things run "normally".  But you said it was smoking, which it should not.
  The voltage at the zener will tell you.  If you have 33V there, then the heat is the normal amount.  If there is a fault, you will not have 33V at the zener, but some lower voltage.  (this is assuming the other end of R1 has it's proper approx. 45V)